Fixing PHP timeout

I hate to ask a noob question but …

I have a custom php.ini for a domain under ~/domain.tld/cgi-bin. These are the settings that I want to take effect:

max_execution_time = 300
memory_limit = 64M

I understand that the default memory limit is 90M. I have the above setting just to verify that this setting can be changed.

I made the above change a week ago and php info still reports max_execution_time is 30 and memory_limit is 90M. I was concerned about the timeout being too high and getting auto-degraded, so I’m using the memory_limit as my check just to verify that “some change” should work, but it’s not working.

What do I need to do to “activate” the custom ini?
I really only need this for my WordPress blog where a search engine indexing times-out, so I need to give it more time. Otherwise I don’t really need the whole site to use the custom ini.

I’m asking here because other forum postings and the wiki seem to have a series of try this, then try that, then … It seems to me that a single set of instructions should just work, and that we shouldn’t have to guess at how to engage in php.ini warfare.

Since we’re here, is it realistic to consider having one php.ini for a blog (under a /blog folder) and another one for, say, Drupal which is under a different directory in the same domain? Or is that overkill? If this is valid, then I’m wondering if I’m just putting my ini in the wrong place under /cgi-bin?